1. Field of the Invention
The present general inventive concept relates to a backlight unit and a liquid crystal display (LCD) apparatus employing the same, and more particularly, to a direct light type backlight unit and an LCD apparatus employing the same.
2. Description of the Related Art
An LCD is one type of non-emissive flat panel display and needs an external light source to produce an image since the LCD itself does not emit light. Accordingly, a backlight unit is located behind the LCD and emits light.
Backlight units are classified into direct light type backlight units and edge light type backlight units according to a position in which light sources of the backlight units are arranged. For a direct light type backlight unit, a plurality of light sources disposed beneath the LCD emit light onto an LCD panel. For an edge light type backlight unit, a light source located along a sidewall of a light guide panel (LGP) emits light onto the LCD panel via the LGP.
The direct light type backlight unit may use light emitting diodes (LEDs) that emit Lambertian radiation as a point light source.
FIG. 1 illustrates a typical arrangement of LEDs 5 for a conventional direct light type backlight unit using the LEDs 5 as point light sources. Referring to FIG. 1, the LEDs 5 are arranged in a two-dimensional array on a printed circuit board (PCB) substrate 1 at equal intervals p. When the conventional backlight unit is measured and observed from a front thereof, four corners of the backlight unit appear dark due to a shortage of light on the four corners.